Barber joined Radiocentre from the Radio Advertising Bureau in 2001, prior to the bureau’s incorporation into Radiocentre. His prior career included strategic planner roles in a range of media agencies.

As planning director, Barber has been responsible for developing much of Radiocentre’s research, with a focus on audio effectiveness.

Radiocentre said it would be announcing further changes to its advocacy team in due course.

Matt Payton, chief executive at Radiocentre, said: “Mark has been a joy to work with over the years, as well as a fantastic source of knowledge and inspiration on all matters relating to audio and advertising.

“His body of work is immense and respected around the world. I can only thank him for the massive contribution he’s made to the success of Radiocentre and to commercial radio in the UK.”

Barber said that it was an appropriate moment to step back and “consider a more fractional approach in the next phase of my life”, including spending more time in a non-executive role with independent media agency December19, and on music and writing.

“I consider myself extremely fortunate to have spent the last 25 years working alongside and supported by so many brilliant, clever, funny and hard-working colleagues, not to mention stakeholders and friends across the industry, all tasked with defining and demonstrating the role and effectiveness of audio for advertisers,” he added.

“Hopefully, some of the thinking I’ve contributed – and been lucky enough to share with audio operators around the world – will be deemed to have provided lasting value to the industry that has sustained, challenged and entertained me across this time.”